Group leaders and teamwork in the over-lean production system

Purpose – This study aims to describe how a work team adapted to its fluctuated and severe environment by changing from “lean” to “over-lean” mode. To do this, the author investigated the relations among productivity, the vertical division of labor, and group leaders' behavior in a Japanese automobile assembly plant. Design/methodology/approach – The authors conducted field study at an assembly plant for five months. They collected three plant-level data to investigate the capability of its shop floor: transition of production volume; transition of the number of workers; and productivity. And they collected two types of workforce data: skill map and work shift. Moreover, they videotaped the behavior of group leaders on several days and analyzed them through a time study. Findings – The work team of this study achieved high productivity even in its tough environment. However, the authors' time study of group leaders showed that the group leaders, who usually engage in some management activities outside of the production line, did many tasks within the line. This indicates the team had a weakness toward the change of team members. Changing to this over-lean mode enabled the team to survive in a short-run, but maintaining the mode has a weakness in enhancing long-term competitiveness. Originality/value – This study proposes a balance between the two modes is required for organizations if they are to survive their severe and fluctuating environments.